哲学家就餐

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<sys/ipc.h>
#include<sys/sem.h>
#include<unistd.h>
#include<time.h>
int semid;

union senum{
        int val;
};

void wait_for_2fork(int no)
{
        int left = no;
        int right = (no+1)%5;

        struct sembuf sbs[2] = {
                {left,-1,0}, {right,-1,0} };
        semop(semid,sbs,2);
}
void put_for_2fork(int no)
{

        int left = no;
        int right = (no+1)%5;

        struct sembuf sbs[2] = {
                {left,1,0}, {right,1,0} };